Fan wheel

Abstract

A fan wheel with a hub is centrally supported with respect to a drive and coaxially rotatable with the hub between stops relative to the hub. The fan wheel having fan blades extending radially from the hub are rotatable about their axes in a range delimited by the stops. Overlaying the rotational support between the stops of the hub, a rotational support between the hub and the drive is provided including a planetary drive in operative arrangement with an adjustment control ring of the driven hub. The fan blades are rotatable in the hub about their blade axes, and adjustment of the blade angles of the fan blades via drive connections to the adjustment control ring, which connections operate in a manner superimposed on one another starting from the drive of the fan wheel.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This is a continuation-in-part application of pending international patent application PCT / EP2020 / 025503 filed Nov. 11, 2020 and claiming the priority of German Patent Application No. 10 2019 134 887.0 filed Dec. 18, 2019. The aforesaid pending international application PCT / EP2020 / 025503 and German Patent Application No. 10 2019 134 887.0 are both incorporated herein by reference as though fully set forth.BACKGROUND OF THE INVENTION[0002]Fan wheels with fan blades which extend radially from a fan wheel hub are known in the art. They are used mainly for cooling and for cleaning heat exchanger surfaces by generating an air flow over the heat exchanger surfaces.[0003]There are fan wheel configurations wherein the air flow can be reversed by a reversal of the running direction of the fan wheel, but also configurations wherein the radial fan blades are rotatably supported in the fan wheel hub so that the radial fan blades can be pivoted to pos...

AI Technical Summary

Benefits of technology

The invention describes a way to make a hub that can rotate in a certain direction, but only within a certain range of angles. This is possible because a planetary drive has a very precise ratio of how much it increases or decreases the speed of the rotation. This results in a hub that can rotate in one direction with very precise speed and in the other direction with less precise speed. This helps to make the hub and the rest of the system work together better, and it allows for cheaper manufacturing of the system components.

Problems solved by technology

These possibilities however are limited—in particular with respect to fan wheels with radial fan blades which are rotatably supported in the fan wheel hub—in that the adjustability of the fan blade angles up to opposite flow directions requires certain distances between the fan blades to permit an uninhibited rotation of the fan blades between their opposite end positions.

This results in a large transmission ratio between the small diameter pinions and the large diameter gear ring and, as a result, requires a large drive force for the gear ring for the adjustment of the fan blade angles within the short periods available for the adjustment of the fan blade angles.

This, however results in a large transmission ratio of the drive gear structure to the respective fan blade pinions that is a transmission toward fast within a stop-delimited rotational range of the drive gear structure relative to the hub.

This results in correspondingly large adjustment and acceleration forces, in particular in the transition plane of the fan blades which plane extends normal to the axis of rotation of the fan wheel between the opposite air flow directions.

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